Hi, when I bought my 426 it was shod with spiked tires and I got S12´s "on the side". Yesterday i had decided to change tires and put some grease on the wheel-bearings. Taking the wheels of was a little more work than on the XR600, but no biggie. I Started with the front tire and it was TUFF HARD f***ing work. Sweating like a pig, scraping my knuckles on the spikes, using both hands, one foot and an elbow I eventually got the front tire off. Putting the S12 on was a breeze. Then the rear wheel, it was a whole other story. It was impossible. I got some help, but the only thing we accomplished were starting to bend the rim - I gave up . Found a tireplace to help me, it took two guys an hour to get the effing tire of, busting the rim rubber-thing and the hose(?) were already busted (the base of the valve), so I had to drive to the closest mc-place (wich happen to be the one that I DO NOT LIKE), they robbed me for close to $26 for a new hose(?) back to the tire shop were they fiddled with my replacement tire - eventually got everything together and charged me almost $30 - and I had to fill the car up with gas, an additional $50. My hands ache from yesterday and my wallet hurts from today. Next week I will put the wheels back on the bike, grease all other bearings and the start driving - I hope all this hassle was worth it. Do I really need both "tire locks"? ///Fredrik!